The present invention is related to a semiconductor device. In particular, the present invention is related to a transistor device and a method for manufacturing the transistor device.
A transistor, such as a metal-oxide-semiconductor (MOS) transistor, may be utilized in a power management integrated circuit (IC). For maximizing processing speed and minimizing energy consumption per switch event to optimize the performance of the power management IC, the MOS transistor may require a large current and a low on-state resistance (Ron). Reduction of Ron may enable increase of the number of MOS switches in a given time period.
FIG. 1A and FIG. 1B show a schematic plan view and a schematic cross-sectional view that illustrate a MOS transistor device. The MOS transistor may include a substrate 100′. The MOS transistor may include a gate structure 200′, shallow trench isolation (STI) structure 300′, a source 500′, and a drain 600′, disposed on the substrate 100′. The MOS transistor may include sidewalls 400′ disposed on lateral sides of the gate structure 200′. For minimizing Ron, the channel width of the MOS transistor may be configured substantially large. Nevertheless, the large channel width may result in an undesirably low computing power per unit area, an undesirably large size, and/or an undesirably high manufacturing of the MOS transistor. Some alternative MOS transistor configurations for minimizing Ron may be associated with substantially complicated structures, substantially high costs, and/or other undesirable effects.